Persistent Connections vs. Connection Pooling: Which is Best for High-Volume MySQL Applications?

Comparison of Persistent Connections and Connection Pooling in MySQL

In MySQL, establishing new database connections for each query incurs significant overhead. To address this, two approaches are available: persistent connections and connection pooling. This article explores these options to determine the most suitable approach for a multi-threaded server application handling thousands of requests per second.

Persistent Connections

Persistent connections allow an application to reuse existing database connections rather than establishing new ones for each query. However, contrary to popular belief, persistent connections do not imply that all threads share the same physical connection. Instead, they simply keep open connections that were previously established. Opening connections is a time-consuming process, so this approach reduces the need to repeat it frequently.

Connection Pooling

In connection pooling, a client application maintains a pool of pre-established connections. Each thread accessing the database checks out a connection from the pool and returns it after use. This allows multiple threads to concurrently utilize database connections without waiting for new connections to be established.

Optimal Option for High-Volume Applications

For a multi-threaded application handling a large volume of requests, connection pooling is generally the preferred choice. It allows multiple application threads to share a pool of connections, reducing the likelihood of database requests being blocked.

Connection Acquisition in Connection Pooling

When multiple threads attempt to acquire connections from a pool, it is crucial to determine the appropriate behavior. The two main options are:

• Waiting for a connection: Threads wait until a connection becomes available in the pool.
• Round-robin approach: Threads send requests to connections in the pool sequentially, even if some connections are unavailable.

The optimal approach depends on the specific application requirements. If immediate response times are critical, a round-robin approach may be preferable. However, if blocking threads does not significantly impact performance, waiting for a connection may be more efficient.

In summary, for high-volume multi-threaded applications, connection pooling is the recommended approach to overcome the overhead of persistent connections. It allows concurrent database access while minimizing request blocking by providing a pool of reusable connections.

The above is the detailed content of Persistent Connections vs. Connection Pooling: Which is Best for High-Volume MySQL Applications?. For more information, please follow other related articles on the PHP Chinese website!